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go/src/runtime/sys_freebsd_386.s
Yuval Pavel Zholkover 744ccbb852 runtime: fast clock_gettime call on FreeBSD
Use AT_TIMEKEEP ELF aux entry to access a kernel mapped ring of timehands structs.
The timehands are updated by the kernel periodically, but for accurate measure the
timecounter still needs to be queried.
Currently the fast path is used only when kern.timecounter.hardware==TSC-low
or kern.timecounter.hardware=='ARM MPCore Timecounter',
other timecounters revert back to regular system call.

TODO: add support for HPET timecounter on 386/amd64.

Change-Id: I321ca4e92be63ba21a2574b758ef5c1e729086ad
Reviewed-on: https://go-review.googlesource.com/93156
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-04-18 21:54:26 +00:00

419 lines
7.9 KiB
ArmAsm

// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//
// System calls and other sys.stuff for 386, FreeBSD
// /usr/src/sys/kern/syscalls.master for syscall numbers.
//
#include "go_asm.h"
#include "go_tls.h"
#include "textflag.h"
TEXT runtime·sys_umtx_op(SB),NOSPLIT,$-4
MOVL $454, AX
INT $0x80
MOVL AX, ret+20(FP)
RET
TEXT runtime·thr_new(SB),NOSPLIT,$-4
MOVL $455, AX
INT $0x80
MOVL AX, ret+8(FP)
RET
TEXT runtime·thr_start(SB),NOSPLIT,$0
MOVL mm+0(FP), AX
MOVL m_g0(AX), BX
LEAL m_tls(AX), BP
MOVL m_id(AX), DI
ADDL $7, DI
PUSHAL
PUSHL $32
PUSHL BP
PUSHL DI
CALL runtime·setldt(SB)
POPL AX
POPL AX
POPL AX
POPAL
get_tls(CX)
MOVL BX, g(CX)
MOVL AX, g_m(BX)
CALL runtime·stackcheck(SB) // smashes AX
CALL runtime·mstart(SB)
MOVL 0, AX // crash (not reached)
// Exit the entire program (like C exit)
TEXT runtime·exit(SB),NOSPLIT,$-4
MOVL $1, AX
INT $0x80
MOVL $0xf1, 0xf1 // crash
RET
GLOBL exitStack<>(SB),RODATA,$8
DATA exitStack<>+0x00(SB)/4, $0
DATA exitStack<>+0x04(SB)/4, $0
// func exitThread(wait *uint32)
TEXT runtime·exitThread(SB),NOSPLIT,$0-4
MOVL wait+0(FP), AX
// We're done using the stack.
MOVL $0, (AX)
// thr_exit takes a single pointer argument, which it expects
// on the stack. We want to pass 0, so switch over to a fake
// stack of 0s. It won't write to the stack.
MOVL $exitStack<>(SB), SP
MOVL $431, AX // thr_exit
INT $0x80
MOVL $0xf1, 0xf1 // crash
JMP 0(PC)
TEXT runtime·open(SB),NOSPLIT,$-4
MOVL $5, AX
INT $0x80
JAE 2(PC)
MOVL $-1, AX
MOVL AX, ret+12(FP)
RET
TEXT runtime·closefd(SB),NOSPLIT,$-4
MOVL $6, AX
INT $0x80
JAE 2(PC)
MOVL $-1, AX
MOVL AX, ret+4(FP)
RET
TEXT runtime·read(SB),NOSPLIT,$-4
MOVL $3, AX
INT $0x80
JAE 2(PC)
MOVL $-1, AX
MOVL AX, ret+12(FP)
RET
TEXT runtime·write(SB),NOSPLIT,$-4
MOVL $4, AX
INT $0x80
JAE 2(PC)
MOVL $-1, AX
MOVL AX, ret+12(FP)
RET
TEXT runtime·raise(SB),NOSPLIT,$16
// thr_self(&8(SP))
LEAL 8(SP), AX
MOVL AX, 4(SP)
MOVL $432, AX
INT $0x80
// thr_kill(self, SIGPIPE)
MOVL 8(SP), AX
MOVL AX, 4(SP)
MOVL sig+0(FP), AX
MOVL AX, 8(SP)
MOVL $433, AX
INT $0x80
RET
TEXT runtime·raiseproc(SB),NOSPLIT,$16
// getpid
MOVL $20, AX
INT $0x80
// kill(self, sig)
MOVL AX, 4(SP)
MOVL sig+0(FP), AX
MOVL AX, 8(SP)
MOVL $37, AX
INT $0x80
RET
TEXT runtime·mmap(SB),NOSPLIT,$32
LEAL addr+0(FP), SI
LEAL 4(SP), DI
CLD
MOVSL
MOVSL
MOVSL
MOVSL
MOVSL
MOVSL
MOVL $0, AX // top 32 bits of file offset
STOSL
MOVL $477, AX
INT $0x80
JAE ok
MOVL $0, p+24(FP)
MOVL AX, err+28(FP)
RET
ok:
MOVL AX, p+24(FP)
MOVL $0, err+28(FP)
RET
TEXT runtime·munmap(SB),NOSPLIT,$-4
MOVL $73, AX
INT $0x80
JAE 2(PC)
MOVL $0xf1, 0xf1 // crash
RET
TEXT runtime·madvise(SB),NOSPLIT,$-4
MOVL $75, AX // madvise
INT $0x80
// ignore failure - maybe pages are locked
RET
TEXT runtime·setitimer(SB), NOSPLIT, $-4
MOVL $83, AX
INT $0x80
RET
// func fallback_walltime() (sec int64, nsec int32)
TEXT runtime·fallback_walltime(SB), NOSPLIT, $32-12
MOVL $232, AX // clock_gettime
LEAL 12(SP), BX
MOVL $0, 4(SP) // CLOCK_REALTIME
MOVL BX, 8(SP)
INT $0x80
MOVL 12(SP), AX // sec
MOVL 16(SP), BX // nsec
// sec is in AX, nsec in BX
MOVL AX, sec_lo+0(FP)
MOVL $0, sec_hi+4(FP)
MOVL BX, nsec+8(FP)
RET
// func fallback_nanotime() int64
TEXT runtime·fallback_nanotime(SB), NOSPLIT, $32-8
MOVL $232, AX
LEAL 12(SP), BX
MOVL $4, 4(SP) // CLOCK_MONOTONIC
MOVL BX, 8(SP)
INT $0x80
MOVL 12(SP), AX // sec
MOVL 16(SP), BX // nsec
// sec is in AX, nsec in BX
// convert to DX:AX nsec
MOVL $1000000000, CX
MULL CX
ADDL BX, AX
ADCL $0, DX
MOVL AX, ret_lo+0(FP)
MOVL DX, ret_hi+4(FP)
RET
TEXT runtime·asmSigaction(SB),NOSPLIT,$-4
MOVL $416, AX
INT $0x80
MOVL AX, ret+12(FP)
RET
TEXT runtime·sigfwd(SB),NOSPLIT,$12-16
MOVL fn+0(FP), AX
MOVL sig+4(FP), BX
MOVL info+8(FP), CX
MOVL ctx+12(FP), DX
MOVL SP, SI
SUBL $32, SP
ANDL $~15, SP // align stack: handler might be a C function
MOVL BX, 0(SP)
MOVL CX, 4(SP)
MOVL DX, 8(SP)
MOVL SI, 12(SP) // save SI: handler might be a Go function
CALL AX
MOVL 12(SP), AX
MOVL AX, SP
RET
TEXT runtime·sigtramp(SB),NOSPLIT,$12
MOVL signo+0(FP), BX
MOVL BX, 0(SP)
MOVL info+4(FP), BX
MOVL BX, 4(SP)
MOVL context+8(FP), BX
MOVL BX, 8(SP)
CALL runtime·sigtrampgo(SB)
// call sigreturn
MOVL context+8(FP), AX
MOVL $0, 0(SP) // syscall gap
MOVL AX, 4(SP)
MOVL $417, AX // sigreturn(ucontext)
INT $0x80
MOVL $0xf1, 0xf1 // crash
RET
TEXT runtime·sigaltstack(SB),NOSPLIT,$0
MOVL $53, AX
INT $0x80
JAE 2(PC)
MOVL $0xf1, 0xf1 // crash
RET
TEXT runtime·usleep(SB),NOSPLIT,$20
MOVL $0, DX
MOVL usec+0(FP), AX
MOVL $1000000, CX
DIVL CX
MOVL AX, 12(SP) // tv_sec
MOVL $1000, AX
MULL DX
MOVL AX, 16(SP) // tv_nsec
MOVL $0, 0(SP)
LEAL 12(SP), AX
MOVL AX, 4(SP) // arg 1 - rqtp
MOVL $0, 8(SP) // arg 2 - rmtp
MOVL $240, AX // sys_nanosleep
INT $0x80
RET
/*
descriptor entry format for system call
is the native machine format, ugly as it is:
2-byte limit
3-byte base
1-byte: 0x80=present, 0x60=dpl<<5, 0x1F=type
1-byte: 0x80=limit is *4k, 0x40=32-bit operand size,
0x0F=4 more bits of limit
1 byte: 8 more bits of base
int i386_get_ldt(int, union ldt_entry *, int);
int i386_set_ldt(int, const union ldt_entry *, int);
*/
// setldt(int entry, int address, int limit)
TEXT runtime·setldt(SB),NOSPLIT,$32
MOVL address+4(FP), BX // aka base
// see comment in sys_linux_386.s; freebsd is similar
ADDL $0x4, BX
// set up data_desc
LEAL 16(SP), AX // struct data_desc
MOVL $0, 0(AX)
MOVL $0, 4(AX)
MOVW BX, 2(AX)
SHRL $16, BX
MOVB BX, 4(AX)
SHRL $8, BX
MOVB BX, 7(AX)
MOVW $0xffff, 0(AX)
MOVB $0xCF, 6(AX) // 32-bit operand, 4k limit unit, 4 more bits of limit
MOVB $0xF2, 5(AX) // r/w data descriptor, dpl=3, present
// call i386_set_ldt(entry, desc, 1)
MOVL $0xffffffff, 0(SP) // auto-allocate entry and return in AX
MOVL AX, 4(SP)
MOVL $1, 8(SP)
CALL runtime·i386_set_ldt(SB)
// compute segment selector - (entry*8+7)
SHLL $3, AX
ADDL $7, AX
MOVW AX, GS
RET
TEXT runtime·i386_set_ldt(SB),NOSPLIT,$16
LEAL args+0(FP), AX // 0(FP) == 4(SP) before SP got moved
MOVL $0, 0(SP) // syscall gap
MOVL $1, 4(SP)
MOVL AX, 8(SP)
MOVL $165, AX
INT $0x80
JAE 2(PC)
INT $3
RET
TEXT runtime·sysctl(SB),NOSPLIT,$28
LEAL mib+0(FP), SI
LEAL 4(SP), DI
CLD
MOVSL // arg 1 - name
MOVSL // arg 2 - namelen
MOVSL // arg 3 - oldp
MOVSL // arg 4 - oldlenp
MOVSL // arg 5 - newp
MOVSL // arg 6 - newlen
MOVL $202, AX // sys___sysctl
INT $0x80
JAE 4(PC)
NEGL AX
MOVL AX, ret+24(FP)
RET
MOVL $0, AX
MOVL AX, ret+24(FP)
RET
TEXT runtime·osyield(SB),NOSPLIT,$-4
MOVL $331, AX // sys_sched_yield
INT $0x80
RET
TEXT runtime·sigprocmask(SB),NOSPLIT,$16
MOVL $0, 0(SP) // syscall gap
MOVL how+0(FP), AX // arg 1 - how
MOVL AX, 4(SP)
MOVL new+4(FP), AX
MOVL AX, 8(SP) // arg 2 - set
MOVL old+8(FP), AX
MOVL AX, 12(SP) // arg 3 - oset
MOVL $340, AX // sys_sigprocmask
INT $0x80
JAE 2(PC)
MOVL $0xf1, 0xf1 // crash
RET
// int32 runtime·kqueue(void);
TEXT runtime·kqueue(SB),NOSPLIT,$0
MOVL $362, AX
INT $0x80
JAE 2(PC)
NEGL AX
MOVL AX, ret+0(FP)
RET
// int32 runtime·kevent(int kq, Kevent *changelist, int nchanges, Kevent *eventlist, int nevents, Timespec *timeout);
TEXT runtime·kevent(SB),NOSPLIT,$0
MOVL $363, AX
INT $0x80
JAE 2(PC)
NEGL AX
MOVL AX, ret+24(FP)
RET
// int32 runtime·closeonexec(int32 fd);
TEXT runtime·closeonexec(SB),NOSPLIT,$32
MOVL $92, AX // fcntl
// 0(SP) is where the caller PC would be; kernel skips it
MOVL fd+0(FP), BX
MOVL BX, 4(SP) // fd
MOVL $2, 8(SP) // F_SETFD
MOVL $1, 12(SP) // FD_CLOEXEC
INT $0x80
JAE 2(PC)
NEGL AX
RET
// func cpuset_getaffinity(level int, which int, id int64, size int, mask *byte) int32
TEXT runtime·cpuset_getaffinity(SB), NOSPLIT, $0-28
MOVL $487, AX
INT $0x80
JAE 2(PC)
NEGL AX
MOVL AX, ret+24(FP)
RET
GLOBL runtime·tlsoffset(SB),NOPTR,$4